- Definition of CaO
CaO, commonly known as quicklime or Calcium Oxide in English, is an inorganic chemical compound. It is a white, odorless solid with an atomic mass of 56.0774(14) u. CaO consists of two atoms, one Calcium atom (Ca) and one Oxygen atom (O), with atomic masses of 40.078(4) u and 15.9994(3) u, respectively. In CaO, the Calcium cation (Ca2+) and the Oxide anion (O2-) bond with each other in a 1:1 ratio to form this compound.
- Properties of CaO
CaO is a white, odorless powder solid at room conditions and has a very high basic pH (about 12-13) when dissolved in water. In chemistry, CaO is highly reactive with water to form Ca(OH)2, a reaction that is an exothermic process.
- Common chemical equations involving CaO
CaO can react with acids (such as hydrochloric acid HCl, sulfuric acid H2SO4,…) to form salts and water. CaO + 2HCl -> CaCl2 + H2O
CaO + H2O -> Ca(OH)2
CaO + H2SO4 -> CaSO4 + H2O
CaO + CO2 -> CaCO3
CaO + SO2 -> CaSO3
CaO + 2SO3 -> CaSO4 - Preparation of CaO
In the laboratory, CaO is usually prepared by heating limestone (CaCO3) at high temperatures. In industry, the process of heating limestone in a cylindrical kiln is used to produce CaO on a large scale.